The research material included in the Abdominal and Direct Fetal
Electrocardiogram Database contains multichannel fetal electrocardiogram (FECG)
recordings obtained from 5 different women in labor, between
38 and 41 weeks of gestation. The recordings were acquired in the Department of
Obstetrics at the Medical University of Silesia, by means of the KOMPOREL
system for acquisition and analysis of fetal electrocardiogram (ITAM
Institute, Zabrze, Poland). Each recording comprises four differential signals
acquired from maternal abdomen and the reference direct fetal electrocardiogram
registered from the fetal head.

The configuration of the abdominal electrodes comprised four electrodes
placed around the navel, a reference electrode placed above the pubic symphysis
and a common mode reference electrode (with active-ground signal) placed on the
left leg. To reduce the skin impedance, the areas under the Ag-AgCl electrodes
were abraded. In all cases, the scalp electrode was placed for a clinical
indication and all women consented to participate in this study.

The acquisition of direct fetal electrocardiogram was carried out with
a typical spiral electrode, commonly used in a direct FECG channel of popular
fetal monitors. The R-wave locations were automatically determined in the
direct FECG signal by means of on-line analysis applied in the KOMPOREL system.
These locations were then verified (off-line) by a group of cardiologists,
resulting in a set of reference markers precisely indicating the R-wave
locations. The markers have been stored together with the direct and indirect
FECG signals in EDF/EDF+ format.

The provided recordings constitute an excellent material for testing and
evaluation of efficacy of new FECG processing techniques, e.g. algorithms for
suppression of maternal electrocardiogram in abdominal signals or for detection
of fetal QRS complexes. In the authors' studies (1-4 above), these recordings
were used to evaluate the accuracy of fetal heart rate measurement and to
estimate its influence on the quantification of the beat-to-beat fetal heart
rate (FHR) variability.